The embodiments herein relate generally to subterranean formation operations and, more particularly, to treatment fluids comprising anhydrous ammonia for use in subterranean formation operations.
Subterranean formations (e.g., hydrocarbon producing wells) are often stimulated by hydraulic fracturing treatments. In hydraulic fracturing treatments, a treatment fluid is pumped into a portion of a subterranean formation at a rate and pressure such that the subterranean formation breaks down and one or more fractures are formed. Typically, particulate solids are then deposited in the fractures. These particulate solids (“proppant particulates” or “proppant”) serve to prevent the fractures from fully closing once the hydraulic pressure is removed by forming a proppant pack. As used herein, the term “proppant pack” refers to a collection of proppant particulates in a fracture. By keeping the fracture from fully closing, the proppant particulates aid in forming conductive paths through which fluids may flow.
Subterranean formations may additionally be stimulated by acid treatments (“acidizing”). Acidizing involves introducing an acidic fluid into the formation to dissolve acid-soluble materials that may clog or constrict formation channels, such as the conductive paths formed between proppant particulates in a proppant pack. Acidic fluids may remove or reduce gas hydrates, among other materials, thus allowing produced fluids from the formation to flow more readily or easily through the formation and into a wellbore for production. Acidizing may also facilitate the flow of injected treatment fluids from the wellbore into the formation, when it is desired. In some instances, hydraulic fracturing may be performed using an acidic treatment fluid (“acid fracturing”).
Stimulation operations, and other subterranean formation operations, are designed to maximize production of fluids therefrom. When production is underway, up-front costs can be recouped provided that operating costs remain low enough for the sale of oil and/or gas to be profitable. Additionally, midstream and downstream processing costs of produced hydrocarbons (i.e., oil and natural gas, which may collectively be referred to herein simply as “oil”) may affect the profitability of the produced hydrocarbons. Gas hydrate production in cold climates, in deepwater environments, or at any point during hydrocarbon production may interfere with this profitability. Gas hydrates are a form of a unique class of chemical compounds known as clathrates. Gas hydrates are characterized by a rigid, open network of bonded host molecules that enclose, without direct chemical bonding, appropriately sized guest molecules of another substance. For example, in the case of gas hydrates a crystalline water molecule acts as the host molecule, which forms a “cage” around a smaller hydrocarbon molecule (e.g., methane), thereby yielding ice-like crystals of gas and water. These gas hydrates tend to adhere to each other, resulting in large ice-like crystals formed on the surface of hydrocarbon conduits that act as blockades (“gas hydrate plugs”).